Menopon are a genus of chewing lice that are common ectoparasites of chickens. There are four species within this genus which affect chickens---M. gallinae, M. pallidum, M. subgallinae, and M. trigonocephalus. M. gallinae is one of the most common types of lice found in backyard and free-range chickens worldwide. They are frequently referred to as the "Shaft Louse".
Menopon are 2 mm long with pale yellow bodies. They move very fast, and will scatter when exposed to light. They live on the shafts of newly grown feathers along the bird's breast and thigh areas. The female's eggs are found cemented individually at the base of the feather shaft or along the feather barb.